System and method for real time assay monitoring

ABSTRACT

A real time assay monitoring system and method can be used to monitor reagent volume in assays for fluid replenishment control, monitor assays in real-time to obtain quality control information, monitor assays in real-time during development to detect saturation levels that can be used to shorten assay time, and provide assay results before the assay is complete, enabling reflex testing to begin automatically. The monitoring system can include a real time imaging system with a camera and lights to capture images of the assay. The captured images can then be used to monitor and control the quality of the staining process in an assay, provide early assay results, and/or to measure the on-site reagent volume within the assay.

RELATED APPLICATIONS

This is a continuation of International Patent Application No.PCT/EP2016/082377, filed Dec. 22, 2016, which claims priority to and thebenefit of U.S. Provisional Application No. 62/430,826, filed Dec. 6,2016, and further claims priority to and the benefit of U.S. ProvisionalApplication No. 62/273,232, filed Dec. 30, 2015. These prior patentapplications are incorporated by reference herein.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to systems and methods for realtime assay monitoring. More particularly, the present disclosure relatesto systems and method for utilizing real time assay monitoring forquality control, repeat testing and reflex testing before samplepreparation is completed.

BACKGROUND

An assay is an analytical procedure that can be performed to measure oneor more properties associated with a biological specimen, for example,and array of molecules, a tissue section or a preparation of cells. Insome assays, specimens may be processed for analysis by applying one ormore fluids to the specimens. For example, microscope slides bearingbiological specimens may be treated with one or more dyes or reagents toadd color and contrast to otherwise transparent or invisible cells orcell components. Immunohistochemical (IHC) and in situ hybridization(ISH) assay staining procedures can be used to process tissue specimensand provide information regarding the presence, location and/or amountof particular molecules in a sample.

Assay and platform development as well as commercial assay testing canbe costly in terms of time and resources, particularly when tests failand must be repeated. Currently, tissue staining quality of a specimenundergoing an assay is evaluated by a pathologist only after the assayis completed, and the pathologist does not have any access to the slidebefore the specimen leaves the assay processing platform. This processcan take up to 13 hours for ISH assays. During assay and platformdevelopment, the same experimental conditions can be repeatedlyperformed to produce results, which then are evaluated by a pathologist,again, only after the assay is completed, to ensure consistent outcomesfor the assays. Information about where and when any failures in thestaining process occurred is unknown to the pathologist, and platformdevelopers are left to run entire batteries of assays to find the rootcause of failures that need to be fixed.

Laboratories could use a solution that addresses the limitedavailability of stain quality control information during sampleprocessing so that should problems arise, a new test could be started ora precious sample could be rescued by performing some remedialprocedure. Additionally, it would be advantageous if assays could bemonitored such that they are not run longer than needed, or even better,if preliminary results could be made available prior to assaycompletion. Preliminary results not only could allow laboratories toimprove efficiency by running tests only as long as needed, but couldalso permit a laboratory (or healthcare provider) to order/startadditional tests indicated by such preliminary tests results. Patientsthat depend on complete test results for diagnoses of their conditionsare also appreciative of a faster time to first result, and thankful toavoid the need to provide an additional sample for testing, assumingthat is even possible.

SUMMARY

The present disclosure is directed to digital pathology tools thatprovide electronic results of assay outcomes and stain quality, which insome embodiments is provided early in the assay such that problems canbe addressed and/or new samples can be started much sooner than if thesample requires a read by a pathologist to determine test quality. Inone embodiment, a digital pathology tool can include a real timemonitoring system with automated scoring that can score the slides froman assay. In a particular embodiment, the real time monitoring systemcan provide a “saturation index,” which is a score that correlates to asignal intensity score. By providing the saturation index in real time,the real time monitoring system can be used to evaluate assay quality inreal time while the assay is occurring. The generation of the saturationindex can be automated in the real time monitoring system and used forvarious assay monitoring applications, such as the monitoring of assayswith various protocols, while the assays are occurring. In addition, theresults of assay outcome can be obtained in real time, before the assayis complete, the slide is “coverslipped,” and then examined by apathologist.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawings(s) will be provided by the Office upon request andpayment of the necessary fee.

FIG. 1 schematically shows an embodiment of a real time assay monitoringsystem.

FIG. 2 shows an embodiment of an imaging system and a sample processingsystem for the real time assay monitoring system depicted by FIG. 1.

FIG. 3 schematically shows an embodiment of a controller for the realtime assay monitoring system depicted by FIG. 1.

FIG. 4 shows an exemplary image used for boundary detection.

FIG. 5 shows another exemplary image used for boundary detection.

FIG. 6 shows an embodiment of a process for determining an amount ofadjustment fluid for an assay.

FIG. 7A shows a first position for the fluid in the system of FIG. 2.

FIG. 7B shows a second position for the fluid in the system of FIG. 2.

FIG. 7C shows a third position for the fluid in the system of FIG. 2.

FIG. 7D shows a fourth position for the fluid in the system of FIG. 2.

FIG. 8 shows an exemplary screenshot of a graphical user interface (GUI)displayed by a real time adjustment system, the single screenshotshowing four individual displayed panels which provide information (e.g.current image, foreground, current volume, and replenishment amount) tothe user based on the process illustrated in FIG. 6.

FIG. 9 shows an embodiment of a process for monitoring an assay.

FIG. 10 shows an embodiment of an HSV color model.

FIG. 11 shows an embodiment of a captured image with a region ofinterest selected.

FIG. 12 shows an embodiment of matrix values corresponding to the regionof interest in FIG. 11.

FIG. 13 shows an exemplary graph of a correlation between signalintensity scores and saturation indexes.

FIG. 14 shows an exemplary graph of a correlation between signalintensity scores and value indexes.

FIG. 15A shows an exemplary graph of the saturation index of a specimenover time.

FIG. 15B illustrates a series of images captured from which a saturationindex comparison may be performed.

FIG. 16A shows another exemplary graph of saturation index of a specimenover time.

FIG. 16B illustrates a series of images captured from which a saturationindex comparison may be performed.

FIG. 17 shows an embodiment of an image analysis process for monitoringstaining in a system.

FIG. 18A shows an example of the results for several different schemesof color space conversion followed by conversion to grayscale.Specifically, FIG. 18A shows images visually illustrating the process oftissue identification as described with regard to the process of FIG.17.

FIG. 18B shows an example of the results for several different schemesof color space conversion followed by conversion to grayscale.Specifically, FIG. 18B visually demonstrates the processes of colorsegmentation and scoring as described in FIG. 17, but furtherillustrating several embodiments of color space conversions that arepossible alternatives.

FIGS. 19A-19D show a comparison of several schemes of color spaceconversion followed by conversion to grayscale.

FIG. 19A illustrates a brown grayscale image and the resulting histogramderived from the image.

FIG. 19B illustrates a brown saturation image and the resultinghistogram derived from the image.

FIG. 19C illustrates a blue grayscale image and the resulting histogramderived from the image.

FIG. 19D illustrates a light blue saturation image and the resultinghistogram derived from the image.

FIG. 20 shows a comparison of results obtained using a disclosedautomated real-time method for stain intensity scoring based onsaturation with intensity scoring through visual pathological scoring

FIG. 21 shows a comparison results obtained using a disclosed automatedreal-time method for stain intensity scoring based on color spaceconversion and grayscale conversion with intensity scoring throughvisual pathological scoring

FIG. 22 shows a disclosed grayscale intensity index vs. antibodyincubation time.

FIGS. 23A and 23B show a disclosed automated method for real-timecalculation of percent positive cells for a CD20 IHC assay.

FIG. 23A illustrates that a real-time assay monitoring system can beused, for example, to calculate a percentage of positive cells of in theCD20, where in the CD20 assay, three colors are evident in the images:brown for the DAB signal, light blue for the counterstaining signal anda white background.

FIG. 23B illustrates that the process of k-means clustering in HSV colorspace can be used to separate brown from other colors. FIG. 23B furtherillustrates that an index based on pixels instead of cells may becalculated, wherein the percentage positive cells is calculated bydividing the number of brown pixels by the sum of brown and blue pixelsand multiplying by 100.

FIGS. 24A and 24B show a disclosed automated method for real-timeseparation of different stain colors in a multiplexed assay.

FIG. 24A illustrates an image stained by DAB (brown) and a Redchromogen. The original image may be separated into red, blue(counterstain), and red channels, as well as a residual channel.

FIG. 24B illustrates that the process of k-means clustering in RGHBcolor space may be an optimal solution for color detection in a DAB/Redassay.

Wherever possible, the same reference numbers are used throughout thedrawings to refer to the same or like parts.

DETAILED DESCRIPTION

The present application generally pertains to a real time assaymonitoring system (RTAMS) that can monitor fluid volume in assays forvolume adjustment control, monitor stain process quality in real-time,and/or output test results in real-time. In one embodiment, thedisclosed system includes a real time imaging system to obtain images ofa sample undergoing a processing step (such as staining, de-staining,bluing or differentiation) to calculate a saturation index thatcorrelates to a signal intensity score. The RTAMS can use the calculatedsaturation index to monitor the signal intensity of assays in real timeand predict assay outcomes before they are complete. The imaging systemin the RTAMS can be used to measure the on-site fluid volume with thespecimen to control the system to overcome any fluid evaporation issuesthat may occur in an assay process. The imaging system in the RTAMS canalso be applied, for example, to monitor an assay by tracking changes intissue color(s) and other image based characteristics to predict assayoutcomes or results. With the capability to monitor an assay while theassay is ongoing, the RTAMS can be a developmental tool to develop newreagents, assays, or platforms. Tissue, slide and stain quality can alsobe tracked in real time for quality assurance, and users alerted earlyin the process such that remedial measures can be taken. Furthermore,the RTAMS can function as a diagnostic tool, enabling and supportingearly digital reporting of patient results before an assay is complete,and even ordering repeat or reflex tests based on the results as theydevelop. The RTAMS may also serve as a digital pathology tool to supportearly electronic reporting of assay results and in some embodimentscould replace the use of scanners used for analysis of completed assayresults.

One aspect of the certain embodiments of the disclosed system and methodis the ensuring of stain quality by monitoring and controlling assayoutcomes.

Another aspect of the certain embodiments of the disclosed system andmethod is the ability to provide a faster result of stain quality inreal time before the assay is complete, and permit remediation of anyquality issues by alerting a user to possible quality issue, or even toautomatically order a second test so that ordering such a test does notrequire a delay in time for a pathologist to read the test results andrequest the test due to quality issues evident in a finished assay.

Another aspect of certain embodiments of the disclosed system and methodis the ability to optimize newly developed reagents, assays, andplatforms to provide assay protocols that take less time or that can beautomatically stopped when sufficiently developed, thereby shorteningassay time “on-the-fly.”

Other features and advantages of various embodiments of the disclosedsystem and method will be apparent from the following more detaileddescription of the identified embodiments, taken in conjunction with theaccompanying drawings which show, by way of example, the principles ofthe disclosure.

FIG. 1 shows an embodiment of a real time assay monitoring system 10.The system 10 includes a controller 12 that can be used to control animaging system 15 and a sample processing system 21. In one embodiment,the sample processing system 21 can use a thin-film technology with lowfluid volumes, however, in other embodiments, the sample processingsystem 21 can use “puddle” technology wherein reagents are applieddirectly onto substrates, such as slides, on which a tissue or cellsample is placed. In one embodiment as shown in FIG. 1, one controller12 can be used to control all of the components of the imaging system 15and the sample processing system 21. However, in other embodiments, thecontroller 12 can include more than one controller controlling one ormore components of the imaging system 15 and/or the sample processingsystem 21. The controller 12 (and other distributed controllers) can beconnected to the imaging system 15 (which can include a camera 14, andone or more of a front light source 16 and a back light source 18) andthe sample processing system 21 (which can include, for example, one ormore of a fluid motion mechanism 20, a fluid exchange system 22 and afluid dispense system 24) by a network. In one embodiment, the networkconnecting the controller 12 and the imaging system 15 and the sampleprocessing system 21 can be a local area network (LAN) that uses anEthernet protocol to communicate over the network. However, in otherembodiments, the network may be the Internet, an Intranet, a wide areanetwork (WAN), or any other type of communication network using one ormore communication protocols such as the transmission controlprotocol/Internet protocol (TCP/IP) when using the Internet. In afurther embodiment, the camera 14 can be connected to controller 12using a GigE vision interface, but the camera 14 can, in otherembodiments, be connected to the controller 12 using other types ofinterfaces, such as a USB vision or Camera Link interface. In stillanother embodiment, the controller 12 can connect with other controllersand workflow control software system solutions, for example, to a useralert system 26 or an automated test ordering system 26. The controller12 can further connect and interface with other Internet applicationsand imaging applications.

FIG. 2 shows a particular embodiment of an imaging system 15 and asample processing system 21 of a real time assay monitoring system 10 ofFIG. 1. The imaging system 15 can include a camera 14 and a front lightsource 16 and a back light source 18 as shown in FIG. 2. However, inother embodiments, the imaging system 15 can include more than onecamera 14, more than one front light source 16 and more than one backlight source 18. In one embodiment, some or all of the components of theimaging system 15 can be mounted on the sample processing system 21. Theimaging system 15 can be used to illuminate and capture images of one ormore samples in the sample processing system 21. The sample processingsystem 21 can include a fluid motion mechanism 20 to move fluid in thesample and a fluid exchange system 22 that has a fluid dispenser 24 (seeFIG. 1, not shown in FIG. 2) to add fluid to the sample and a fluidremoval device (not shown) to remove fluid from the sample, whichtogether function as a fluid exchange system 22 (as depicted in FIG. 1).In one embodiment, the fluid motion mechanism 20 can include a roller.However, in other embodiments, the sample processing system may notinclude a fluid motion mechanism 20. The fluid motion mechanism 20(schematically shown in FIG. 2) can include one or more stainingcassettes (not shown) having one or more samples 50 undergoing an assay.In other embodiments, the sample processing system 21 can include morethan one fluid motion mechanism 20 and more than one fluid exchangesystem 22. Examples of sample processing systems that can be used withthe present application are described in commonly-assigned U.S. PatentApplication Publication No. 2015/0323776, entitled “Specimen ProcessingSystems and Methods for Holding Slides” and published on Nov. 12, 2015and commonly-assigned U.S. Pat. No. 8,883,509, entitled “Apparatus andMethod for Biological Sample Processing” and granted on Nov. 11, 2014,which are incorporated herein by reference.

Each of the samples 50 held by cassettes in the sample processing system21 can include a slide 52 holding one or more specimens 54 to beanalyzed by the assay. The sample 50 shown in FIG. 2 is a schematicrepresentation of an assay sample used to show the components in thesample and is not intended to provide any details on the relative sizesof the components. One or more fluids 56, such as reagents and/orstains, can be applied to and/or removed from the specimen 54 with thefluid exchange system 22. In one embodiment, the reagents and/or stains56 can include, but are not limited to, antibody diluent, protease 3,reaction buffer, system fluid, HRP (horseradish peroxidase) inhibitors,antibodies, HQ linker, HRP multimers, H₂O₂, DAB (3,3′-Diaminobenzidine),copper reagent, Hematoxylin (HTX), probe reagent and bluing reagent. Acover 58 can then be placed over the specimen 54 and the reagent and/orstain 56. In one embodiment, the cover 58 can be a clear or translucentsolid plastic or acrylic, but may have different color tints, e.g., ayellow tint, in other embodiments. In a further embodiment, the cover 58can also be a clear fluid.

The camera 14 can be placed a predetermined distance (d) above thesample 50 such that the sample 50 is within the field of view (FOV) ofthe camera 14. In one embodiment, the camera 14 can be an area scancamera with global shutter to prevent the distortion of the movingobject, i.e., the reagent and/or stain 56. However, other types ofcameras can be used in other embodiments.

The camera 14 can be a 1600×1200 pixels (2 megapixel, 2MP) camera with a35 mm fixed focal length lens that has a field of view of 988×740 mmwith about 61.25 μm/pixel resolution. However, in other embodiments, thecamera 14 can have greater than or less than 2 megapixels, a fixed focallength lens that is greater than or less than 35 mm, a field of viewthat is greater than or less than 988×740 mm, and/or a resolution thatis greater than or less than about 61.25 μm/pixel. In still anotherembodiment, the camera 14 can have a pixel scale (or resolution) of 0.16mm or lower. In a further embodiment, the camera 14 can use a 50 mmfixed focal length lens with a smaller FOV but a higher resolution.

The predetermined distance for placement of the camera 14 above thesample 50 can be based on the resolution of the camera 14 and the numberof samples 50 to be captured in the field of view of the camera 14. Inone embodiment, the predetermined distance can be 19.5 inches to capturethree samples 50. However, other predetermined distances can be used inother embodiments. In another embodiment, if more than three samples 50are to be captured, a camera 14 can use a pixel array with an increasedsize and a lens with a decreased focal length to maintain the same imagequality.

The front light source 16 and the back light source 18 can each generatewhite light that is used to illuminate the sample 50. In someembodiments, the front light source 16 and/or the back light source 18can be assembled into a lamp for use with a lighting fixture. As anexample, the light source may be implemented by an incandescent bulb, alight emitting diode (LED), or a fluorescent light. Yet other types oflight sources and types of light are possible in other embodiments. Asshown in the embodiment of FIG. 2, the front light source 16 can bepositioned in the field of view of the camera 14 and direct light (L1)toward one side of the sample 50, while the back light source 18 can bepositioned outside of the field of view of the camera 14 and directlight (L2) toward the opposite side of the sample 50. In otherembodiments, one or both of the front light source 16 and the back lightsource 18 can be either within or outside of the field of view of thecamera 14.

FIG. 3 shows an embodiment of the controller 12. The controller 12 caninclude logic 31, referred to herein as “controller logic,” forgenerally controlling the operation of the controller 12, includingcommunicating with the imaging system 15 and the sample processingsystem 21. The controller 12 also includes a volume estimator 37 todetermine the amount of fluid, e.g., reagent and/or stain 56, being usedwith a sample 50, an image analyzer 33 to analyze the images from theimaging system 15, and a dispenser volume calculator 35 to determine howmuch reagent and/or stain 56 to apply to the sample 50 with the fluidexchange system 22 based on information from the volume estimator 37.The controller logic 31, the image analyzer 33, the dispenser volumecalculator 35 and the volume estimator 37 can be implemented insoftware, hardware, firmware or any combination thereof. In thecontroller 12 shown in FIG. 3, the controller logic 31, the imageanalyzer 33, the dispenser volume calculator 35 and the volume estimator37 are implemented in software and stored in memory 38 of the controller12. Note that the controller logic 31, the image analyzer 33, thedispenser volume calculator 35 and the volume estimator 37, whenimplemented in software, can be stored and transported on anynon-transitory computer-readable medium for use by or in connection withan instruction execution apparatus that can fetch and executeinstructions.

The controller 12 can include at least one conventional processingelement 40, which has processing hardware for executing instructionsstored in memory 38. As an example, the processing element 40 mayinclude a central processing unit (CPU) or a digital signal processor(DSP). The processing element 40 communicates to and drives the otherelements within the controller 12 via a local interface 42, which caninclude at least one bus. Furthermore, an input interface 44, forexample, a keypad, keyboard or a mouse, can be used to input data from auser of the controller 12, and an output interface 46, for example, aprinter, monitor, liquid crystal display (LCD), or other displayapparatus, can be used to output data to the user. Further, acommunication interface 48 may be used to exchange data over one or morenetworks with, for example, the front light source 16, the back lightsource 18, the camera 14, the fluid motion mechanism 20 and the fluidexchange system 22.

The imaging system 15 can be used to obtain quality images of the sample50 for image analysis, volume calculation, and assay sensing. In oneembodiment, the camera 14 can have sufficient resolution (or distanceper pixel) and contrast to capture the fluid edge and the specimen 54 inthe sample 50. In other embodiments, the camera 14 can have higherresolution, i.e., a lower distance per pixel, and a lens with a smallerfield of view to capture images of the sample 50 in more detail. Theimaging system 15 can be used for fluid volume sensing. When sensing ormeasuring fluid volume, the imaging system 15 can use the front lightsource 16 and the back light source 18 to make the fluid boundariesbright so that the controller 12 can differentiate the fluid, e.g.,reagent and/or stain 56, from the specimen 54 in the background, evenwhen the specimen 54 has a color associated with it. In one embodimentas shown in FIG. 2, the back light source 18 can be placed outside ofthe field of view of camera 14 to provide dark field imaging to make thefluid boundary or edge in the sample 50 bright, so the fluid edge orboundary has strong contrast to the dark and normal background. Inaddition, by using dark field imaging, several other issues such asinterference from shadows or a pipette blocking a light source can alsobe resolved. In another embodiment, the front light source 16 and theback light source 18 can be positioned about the sample 50 to provideuniform illumination of the sample 50 so that any determinations by thecontroller 12 using images from the imaging system 15 are not biased orskewed by lighting. In a further embodiment, bright field imaging can beused by the imaging system 15 by placing the front light source 16 inthe field of view of the camera 14.

The real time assay monitoring system 10 can be used as a real timefluid adjustment system (RTFAS) to track the fluid, e.g., the reagentand/or stain, volume in the sample 50 and determine an amount of fluidto be added to or removed from the sample 50, if any, by the fluidexchange system 22. The RTFAS can use the imaging system 15, the imageanalyzer 33, the volume estimator 37, the dispenser volume calculator35, the fluid exchange system 22 and a position signal from fluid motionmechanism 20. When the fluid motion mechanism 20 signals the controller12 that it is time to take a measurement, the controller 12 wouldperform frame checking on the image(s) from the imaging system 15 andsuggest an adjustment amount from dispenser volume calculator 35 tofluid exchange system 22, forming a feedback control loop. In anotherembodiment, the adjustment amount from dispenser volume calculator 35can be provided to a user interface and a user can then control thefluid exchange system 22 to provide the reagent and/or stain 56 to thesample 50.

In one embodiment of the RTFAS, motion-based foreground detection isused to detect the boundary of clear fluid and color-thresholdingforeground detection is used to detect the boundary of a stain orcolored reagent, e.g., hematoxylin. The boundary detection methodologiesused by the RTFAS can use a distinct feature of the fluid (target) forboundary detection and work under various conditions such as changingspecimen color or the existence of random tissue patterns in thespecimen 54.

For a clear fluid, motion can be the most distinct feature because theclear fluid is the only part moving in the field of view. In oneembodiment, a Gaussian mixture model foreground detection algorithm canbe used by the RTFAS for boundary detection of a clear fluid. FIG. 4shows an exemplary image generated by the Gaussian mixture modelforeground detection algorithm used for boundary detection. In theGaussian mixture model foreground detection algorithm, two boundaries ofthe fluid droplet (56 of FIG. 2) located on the right and left of thedroplet can be extracted to calculate the fluid volume.

To identify the edge or boundary of a stain or colored reagent, e.g.,hematoxylin, a color-thresholding foreground detection algorithm can beused because of the distinctive color feature of the fluid. Thecolor-thresholding foreground detection algorithm can be used forboundary detection even if the specimen 54 may get a similar color tothe reagent and/or stain 56 during the staining process because theintensity of the reagent and/or stain 56 is still much stronger than thespecimen 54 so that the algorithm can differentiate reagent and/or stain56 from the stained tissue of the specimen 54. The color-thresholdingforeground detection algorithm can transfer the captured images from theimaging system 15 to an HSV (hue, saturation, and value) color map (seeFIG. 12) for the selection of the proper hue range to extract the regionof reagent and/or stain 56. FIG. 5 shows an exemplary image generated bythe color-thresholding foreground detection algorithm used for boundarydetection of the fluid 56 (of FIG. 2) even when the fluid 56 and tissuesample 54 (of FIG. 2) are of similar colors. Using thecolor-thresholding foreground detection algorithm, the area of thereagent can be extracted and the fluid volume can be calculated from theextracted area.

Referring back to FIG. 1, the controller 12 can be connected to thecamera 14 to receive acquired or captured images from the camera 14. Thecontroller 12 can also be connected to a digital I/O device associatedwith the fluid motion mechanism 20 to receive a digital signalindicative of the sample position of the sample 50 in the stainingcassette. With the image and position signal, the RTFAS can performimage analysis, error checking, and volume calculation to suggest aproper adjustment volume. In one embodiment, the images from the camera14 can be captured at the same sample position and then analyzed forconsistent results. In another embodiment, the image analysis can beperformed on either color or grayscale images.

FIG. 6 shows an embodiment of a process for determining an amount ofadjustment fluid with an RTFAS. The process begins by configuring thecamera 14 (step 102) by setting parameters such as exposure, brightness,and gain. The I/O device can then be configured (step 104). After thecamera 14 and the I/O device have been configured, an image is acquired(step 106) from the camera 14. A foreground detection algorithm can beapplied to the captured image (step 108) by the image analyzer 33 toidentify fluid boundaries. In one embodiment, the image analyzer 33 canbe continuously provided with images or video in order to identify theimage background by machine learning. The image analyzer 33 (see, FIG.3) can remove any noise from the processed image (step 110). An I/Osignal check is then made to determine if a signal indicating the propersample position to make a fluid measurement has been received (step112). If the proper I/O signal has not been received, the processreturns to step 106 to acquire another image.

The sample position, as provided by the I/O signal, can be acquired eachtime an image or frame is acquired in step 106 to identify the positionof the reagent and/or stain 56 in the sample 50 (see FIG. 2). Sampleposition can be determined by the step motor positions in the fluidmotion mechanism 20 (of FIG. 1) that move the staining cassette andsamples 50 and thereby move the reagent and/or stain 56 in the sample50. In one embodiment, the step motor positions and corresponding samplepositions can be around +4500, which indicates one end positioncorresponding to the reagent and/or stain 56 at the right end of theslide 50 (see FIG. 7B), and −4500, which indicates another end positioncorresponding to the reagent and/or stain 56 at the left end of theslide 50 (see FIG. 7A), from a center position. The proper sampleposition for taking a measurement can be when the reagent and/or stain56 is located at the center of the slide 52. FIG. 7C shows the reagentand/or stain 56 at sample position 0, which corresponds to the centerposition, when the reagent and/or stain 56 is moving from right to leftin FIG. 7C, which sample position does not correspond to the reagentand/or stain 56 being in the center of the slide 52. Since the reagentand/or stain 56 is moving in the sample 50, the proper sample positionwould be at a predetermined location relative to the center of the slide(which corresponds to sample position 0) depending on the direction oftravel and the viscosity of the reagent and/or stain 56. In oneembodiment as shown in FIG. 7D, the reagent and/or stain 56 is at themeasurement point, i.e., the reagent and/or stain 56 is in the center ofthe slide, at sample position −300, when the reagent and/or stain 56 ismoving from right to left in the sample 50. The embodiments shown inFIGS. 7A-7D are schematic representations used to show the position ofthe reagent and/or stain 56 relative to sample position and are notintended to provide any details on the relative sizes of the components.

As described above, the reagent and/or stain 56 can be dragging behindthe center of the sample position, so the measurement should be takenslightly away from the central point of the sample position. Forexample, when acquiring images at the central point of the fluid motionmechanism 20, the majority of the reagent and/or stain 56 can be on theleft-hand side of the central point when the reagent and/or stain 56 istravelling to the right and the majority of the reagent and/or stain 56can be on the right-hand side of the central point when the reagentand/or stain 56 is travelling to the left. In one embodiment, the RTFAScan be used to characterize the relationship between the motion of thereagent and/or stain 56 and fluid motion mechanism 20, to understand howreagent and/or stain 56 rolls at different rolling speed and rollingvolume, and to investigate how different reagents with differentviscosities behave during the rolling operation since the RTFAS canacquire images at certain sample positions.

In one embodiment, the RTFAS can check sample position periodically. Adetection mechanism in the fluid motion mechanism 20, which generatesthe I/O signal, can determine if the sample position passes sampleposition −300 when moving from sample position +4500. The detectionmechanism can adjust the I/O signal to a “1” if the sample position isbetween −300 and +4500 and adjust the I/O signal to a “0” in otherpositions. The RTFAS can record or store the I/O signal, and if theprevious I/O signal equals to 1 and the current I/O signal changes to 0,then the RTFAS knows the reagent and/or stain 56 is moving from ansample position of +4500 and just crossed a sample position of −300,which corresponds to the reagent and/or stain 56 being in the properposition for a measurement. In another embodiment, the detectionmechanism can send a signal that corresponds to the sample position andthe RTFAS can evaluate the signal from the detection mechanism todetermine whether the corresponding sample position from the signal iswithin a predetermined range of the predetermined location of the sampleposition. For example, the RTFAS can indicate a positive I/O signal ifthe sample position is between about −200 and −400 when the reagentand/or stain 56 is moving from right to left in the sample 50.

Referring back to FIG. 6, if an I/O signal is received indicating theproper sample position, then a fluid volume is calculated by the volumeestimator 37 (step 114). In one embodiment, the volume of the reagentand/or stain 56 can be calculated based on the system (or “ARC”)geometry and the measured fluid bandwidth or length, i.e., the distancebetween the detected fluid boundaries. In one embodiment, the calculatedvolume may have to be calibrated to account for assumptions used in thevolume calculation and/or other possible matters that may affect theaccuracy of the calculation. A frame check is then performed (step 116)to determine if the frame and corresponding volume calculation areacceptable. The frame check can check for errors such as an excessivevolume change and check for other abnormal frame conditions such as apipette blocking the field of view. If the frame or volume calculationis not acceptable, i.e., there is an error or abnormality associatedwith the frame or the volume calculation, the process returns to step106 to acquire another image. If the frame and volume calculation areacceptable, an adjustment amount is calculated (step 118) by thedispenser volume calculator 35 and the process returns to step 106 toacquire another image.

In one embodiment, an adjustment amount should only be determined whenthe volume calculation is done from a satisfactory image or frame withclear fluid boundaries as can be judged by image processing analyzer 33of FIG. 3. During the staining process, several different types ofevents can occur that can affect the accuracy of the volume estimationand thereby affect the calculation of the adjustment amount. Forexample, a frame with a pipette arm travelling through the field of viewmay yield an excessive calculated volume. To overcome some of theproblems with accurate volume estimation, the ratio of the bright pixelsin a frame is calculated as part of the frame check in step 116 toensure that an adjustment amount is not calculated when bright pixelsrepresents more than 50% of the frame. In other words, an acceptableframe has less than 50% of bright pixels in the frame.

In another embodiment, an accurate volume calculation cannot occur whenone part of the fluid boundary is not in the field of view. For example,the fluid boundary may be out of range, i.e., not in the field of view,when the reagent and/or stain 56 has a large volume, such as 200 μL ormore, and is moving at a high speed, such as more than 100 mm/s. In afurther embodiment, an accurate volume calculation cannot occur when theforeground analysis of step 108 cannot provide a correct fluid boundary.In the above two embodiments, the RTFAS can compare the previous volumeto the current volume. If there is a large difference between the twovolumes, the RTFAS can wait until the next measurement point todetermine the current volume. In other words, when there is a largedifference between two calculated volumes, the frame check in step 116can reject the volume measurement and return the process to step 106 toacquire a new image.

In one embodiment, the RTFAS can provide a user interface for a user tomonitor the process of FIG. 6. FIG. 8 shows an exemplary screenshot of auser interface displayed by the RTFAS. The user interface 140 displayedby the RTFAS can include four panels to provide information to the useron the process of FIG. 6. A first panel 142 shows the current imageacquired by camera 14. A second panel 144 shows the foreground detectedusing the Gaussian Mixture Model or color-thresholding method. A thirdpanel 146 shows the calculated current volume (over time) based on thedetected foreground. A fourth panel 148 shows the calculated adjustmentamount (over time) based on a user-input target volume, an offsetvolume, and the measured volume. As shown in the third panel 146 of FIG.8, a decline of measured volume of about 8 μL can be observed due to theevaporation of the reagent and/or stain 56 during 120 seconds ofrolling.

The RTFAS can detect for the formation of bubbles in the reagent and/orstain 56 and can compensate for the presence of the bubbles in thevolume calculation in step 114. If volume calculation does notcompensate for the presence of bubbles, the volume calculation may beoverestimated because the bubbles formed in the reagent and/or stain 56would increase the measured fluid bandwidth. In one embodiment, bubblesmay form in the reagent and/or stain 56 when antibody diluent is beingused in the sample 50.

In one embodiment, the circular shape of the bubbles inside the fluidcan be used to detect for the presence of the bubbles and then performcompensation for the bubbles. A circle detection scheme can be used toidentify any bubbles in the detected foreground of the acquired image.By calculating the numbers of bubbles in the image and giving propervolume compensations for the bubbles, the volume of the reagent and/orstain 56 can be measured more accurately in the presence of bubbles inthe reagent and/or stain 56.

In one embodiment, the RTFAS can perform image acquisition, sampleposition acquisition, and image analysis in about 0.06 seconds and wouldhave a frame rate of about 16 frames per second. The processing time canbe based on the programming language used to perform the image analysisand the performance of the computer used to execute the image analysis.Improvements in processing time may be obtained by using more efficientprogramming languages or better performing computers.

The real time assay monitoring system 10 can also be used to calculate asaturation index for an assay that corresponds to a signal intensityscore given by a pathologist analyzing the results of the assay with amicroscope at the completion of the assay. The calculated indices, suchas the saturation index, can be obtained from changes in colors on thetissue specimen. The changes in color are captured during a reaction inwhich chromogen colors get deposited on the sample specimen during areaction (e.g., during DAB deposition) and other color uptakes (e.g.dyes and fluorophores used, for example, in multiplexing assays). Thus,the system 10 can monitor and measure an index of a reaction in realtime. In addition, the calculated saturation index can be used tomonitor, in real time, the staining process for the samples 50. Anexample of a staining process that can be used with the presentapplication are described in commonly-assigned U.S. Patent ApplicationPublication No. 2013/0302852, entitled “Hematoxylin Staining Method” andpublished on Nov. 14, 2013, which is incorporated herein by reference.

FIG. 9 shows an embodiment of a process for monitoring the stainingprocess of an assay. The process begins by configuring the camera 14(step 182) by setting parameters such as exposure, brightness, and gain.After the camera 14 has been configured, an image is acquired (step 184)from the camera 14. Each acquired image can be composed of a matrix withvalues representing the color for each pixel. In one embodiment, the HSV(hue, saturation, value) color model can be used. However, in otherembodiments, different color models, such as RGB (red, green, blue),L*A*B*, or YCbCr, can be used. For the HSV color model, the hue indexprovides information, in the form of numbers, about the color of thespecimen 54, the saturation index provides information on the lightnessor darkness of the staining, and the value index, sometimes called thebrightness index, also provides light/dark information on the stain.FIG. 10 shows an embodiment of an HSV color model. As shown in FIG. 10,the hue index (or value) represents the color, a saturation index (orvalue) close to zero refers to a very light color close to white, and avalue index (or value) close to zero refers to a very dark color closeblack. When the saturation index and the value index each reach a peak,a “pure color” is obtained.

Referring back to the process of FIG. 9, a region of interest (ROI) canbe selected (step 186) in the captured image. As shown in FIG. 11, a box202 can be positioned to correspond to the selected for the region ofinterest (ROI) in the acquired image. In one embodiment, an ROI can beselected in a region of the tissue being stained either by a user orautomatically by the system 10. In another embodiment, the same or adifferent ROI can be selected for each acquired image from one sample50. Within the ROI, the image has a number or index representing thelocal intensity for each pixel as shown in FIG. 11. The array ofdifferent intensities corresponding to the pixels in the ROI can beanalyzed and compared to each other. In one embodiment, the ROI can beestablished as the same location of a tissue biopsy that has been placedon different slides. The arrays of the ROIs from the different slidescan be compared to each other, either prior to or during the assayprocess, to provide a baseline. Once the baseline is established, anydifferences between the arrays of the ROIs of processed samples and thebaseline are directed to the result of the assay process. A saturationindex and a signal intensity score for the selected ROI can becalculated (step 188). The calculated saturation index can be convertedto a signal intensity score using a predefined correlation. FIG. 13shows a graph of the correlation between signal intensity scores andsaturation indexes. In one embodiment, the correlation between signalintensity scores and saturation indexes can be made experimentally byperforming staining procedures with different antibody and DABincubation times and recording the saturation index for each of thestaining procedures just before the end of the staining procedure. Theresults of each of the staining procedures can then be provided to apathologist for a signal intensity score which is then correlated to therecorded saturation index.

In another embodiment, the value index can be used instead of thesaturation index to generate the signal intensity score. FIG. 14 shows agraph of the correlation between signal intensity scores and valueindexes. In one embodiment, the correlation between signal intensityscores and value indexes can be made experimentally by performingstaining procedures with different antibody and DAB incubation times andrecording the value index for each of the staining procedures justbefore the end of the staining procedure. The results of each of thestaining procedures can then be provided to a pathologist for a signalintensity score which is then correlated to the recorded value index. Instill another embodiment both the saturation index and the value indexcan both be used to generate a corresponding signal intensity score. Ina further embodiment, the hue index can be used for color detection whenmultiple colors are used to distinguish multiple assay targets in thesame specimen through multiplexing staining procedures since similarcolors are encoded close to each other in numeric values.

The calculated signal intensity score can be used to evaluate thestaining of the specimen (step 189). The calculated signal intensityscore can be used to determine if the staining process is proceeding asexpected while the staining process is still ongoing. A determinationcan then be made as to whether the assay had been completed or should bestopped or modified (step 190). If the assay has been completed becausethe specified incubation time has elapsed or if the assay should bestopped or modified because the signal intensity score indicates aproblem with the staining process, the process ends, otherwise theprocess returns to step 184 to acquire another image.

In one embodiment, the real time assay monitoring system 10 can be usedto ensure tissue staining uniformity. The system 10 can segment thespecimen areas into different ROIs and compare their saturation indexes.If there is a declining or increasing trend of saturation indexes, therecan be a gradient of the staining signal intensity, which occurs in thecase of a non-uniform stained sample. When performing the saturationindex comparison, the saturation index value can be normalized to theslide background to ensure that saturation index differences are notobtained from differences in local lighting conditions.

In another embodiment, the real time assay monitoring system 10 can beused to optimize assay protocols. For example, the real time assaymonitoring system 10 can monitor the saturation index in real time atabout a frame per minute/or less for antibody incubation timeoptimization while maintaining DAB incubation time the same for eachsample. As shown in FIG. 15, 16 minutes of antibody incubation timeresults in the saturation index being above 0.7 after 2 minutes duringthe DAB color reaction, which indicates that the 16 minute antibodyincubation time results in the desired signal intensity for stainquality measurement optimization. If the antibody incubation time isshortened to 8 minutes, the saturation index during the DAB colorreaction can only saturate around 0.68. Further, if the antibodyincubation time is shortened to 3 minutes, the saturation index can onlyreach around 0.66. In another example, the real time assay monitoringsystem 10 can also monitor the saturation index in real time at about aframe per minute for DAB/H₂O₂ incubation time optimization whilemaintaining the antibody incubation time the same for each sample. Asshown in FIG. 16, DAB incubation for only 1 minute shows that thesaturation index just stops while the saturation index is in a sharplyincreasing region, as evidenced by the other samples. For 15 minutes ofDAB incubation, the saturation index rises above 0.7 after 6 minutes andmay indicate that the extra minutes of DAB incubation time are notnecessary. Finally, a DAB incubation time of 6-8 minutes may providebetter results because the signal is allowed to saturate with the timeand there is also a time margin about 2-4 minutes to ensure the signalsaturation. The difference in the saturation index from the differentassay protocols shows that the real time assay monitoring system 10 canbe used to optimize assay protocols, such as antibody incubation timeand/or DAB incubation time.

In one embodiment, the system 10 can discern and measure changes incolor during an assay chromogen reaction. The system 10 can discern thepresence or absence of color, determine the type of color anddistinguish intensity and brightness. By measuring the changes in colorduring the assay chromogen reaction, the system 10 can be used for assayand platform development and extended to quality control monitoring andworkflow monitoring.

In another embodiment, the system 10 can be equipped to provide ascoring assessment of the stain quality in real time. The stain qualityscores provide insight of the assay performance and staining resultsbefore the assay is complete. As the system 10 calculates the resultsobtained from a digital image, preliminary scores can be stored and/orreported electronically for various purposes. The preliminary scores mayaid pathologists and technicians by providing an assessment of the stainquality, initial results of the assay, and preliminary diagnosticassessment of the test case. Thus, the system 10 can be used as adigital pathology tool enabling and supporting early digital reportingof patient results to pathologists before assay procedure is complete.Moreover, data collected throughout the assay procedure can also bestored as part of the slide's barcode as part of a workflow solution.The system 10 can be used to maintain record keeping of the assayworkflow accessible on cloud based workflow software outside of thestaining platform.

In a further embodiment, the system 10 can be used as an assay andreagent development tool. As a development tool, the system 10 canmeasure and profile measurement parameters linked to color change basedon experimental testing for chromogens, reagents and antibodydevelopment. The measured results can help determine the optimalreagent, antibody, chromogen and counterstain incubation times based onpathologist scoring criteria. The measured results provided by thesystem 10 enables determining which experimental conditions of antibody,chromogen detection and counterstain reagents incubations are sufficientand necessary in real time for optimal assay performance in thedevelopment and validation of the assays. The system 10 can be appliedto both fluorescent and non-fluorescent chromogens contingent on havingfilters that permit visual inspection at appropriate wavelengths.Moreover, because the system 10 permits color separation, the system 10can separate multiple different fluorophores and bright field chromogencolors at the same time during multiplexing IHC (immunohistochemistry).Thus multiplexing characterization of staining and validation can beenabled and readily optimized by quantitative parameters obtained withthe system 10. Moreover, the system 10 can be used to implement anyexperimental manipulation including assessment of bulk reagents and testtheir impact on stain quality with the scoring algorithm.

In still another embodiment, the scoring algorithm used by the system 10also enables quality monitoring and evaluation of platform performance.For example, implementation of real time assay monitoring could permitassessment of staining quality linking the potential platform designchanges or platform related testing to the potential impact on stainquality for both primary and advanced staining platforms.

In an additional embodiment, the system 10 can be used with marketedplatforms to monitor consistency in desired stain quality in situationswhere global customers have varying preferences in stain intensity andhue. Thus, the system 10 can enable customers to program stainpreference and hue based on a quantitative scale such as through a touchscreen. The quantitative scale could serve as a metric for real timemonitoring, and evaluating stain preference in a quality controlledapproach. The monitoring system 10 can provide an unbiased quantitativeparameter to distinguish those settings that could be validated bypathologists.

Turning now to FIG. 17, and embodiment of a process 300 for imageanalysis of DAB signal intensity is shown, which process can be used formonitoring stain process progression (for example, for quality controlor assay development) that could trigger a user alert or for providingearly results of an assay (such as a threshold % positivity of cellshaving a particular biomarker) that could trigger the automatic orderingof a reflex test to investigate for a correlated biomarker that couldaid in a patient diagnosis. Once the controller of the system triggers302 image acquisition 304, the image analysis system then identifies thetissue through a process of basic registration 306, edge detection 308,filtering of noise 310, formation of a binary mask 312 (a process thatcan include dilation, filling and image erosion as is shown in FIG. 18),and production of a cropped image 314. The cropped image 314 is thenfurther analyzed to segment that different colors in the images by, forexample, K-means clustering 316, RGB thresholding 318, selection of anROI 320 and generation of a positive signal image 322. The positivesignal image 322 is then scored in this embodiment by first making acolor space conversion 324, conversion to grayscale 326, and generationof an average score 328.

Panel A of FIG. 18 shows images visually illustrating the process oftissue identification as described with regard to the process of FIG.17. Panel B of FIG. 18 visually demonstrates the processes of colorsegmentation and scoring as described in FIG. 17, but furtherillustrating several embodiments of color space conversions that arepossible alternatives.

FIG. 19 illustrates additional types of average grayscale and saturationscores that can be generated according to additional embodiments of thedisclosed system and method and that can be used to assess stain processprogression and quality.

The correlation between pathologists' signal intensity score wasinvestigated when the staining system was a “puddle” system as opposedto the thin film staining system of FIG. 2. Two indices were consideredfor the scoring approach for signal intensity score of stained tissuesin RTAMS: one was a grayscale intensity converted from RGB color space,and the other was the saturation index in HSV color space, which wasused successfully in the thin-film staining environment.

Grayscale images contain multiple shades of gray in between black andwhite. Grayscale index was chosen because each pixel only carriesintensity information after colorimetric conversion from RGB color spaceor another color space. 8-bit grayscale index format converted from RGBcolor space was applied. This index varies from black as absoluteabsence of intensity (0 out of 255) to white as absolute presence ofintensity (255 out of 255), and thus is inversely proportional to anintensity score provided by pathologist, since a darker signal willreceive higher intensity score from pathologists but a lower index valuefrom grayscale. As described and shown in FIGS. 17 and 18, edgedetection was used to create a binary mask that separated the sectioncontaining tissue from the entire acquired image including some imagedilation and erosion. Next, color segmentation was used to separate thestains by colors, which are positive signals, counterstain signal andbackground. Different color segmentation strategies had been tested butk-means clustering for setting thresholds in RGB color space works wellfor the CD20 assay in the puddle environment.

In order to demonstrate the utility of grayscale and saturation as RTAMSscores for monitoring assay progression in the puddle environment, thecorrelation of both indices to pathologists' intensity score wasestablished. Various incubation times of CD20 antibody and Hematoxylinwere chosen to create different intensity levels of positive signal andcounterstain signal on tonsil tissues following a standard DAB detectionprotocol (UltraView DAB, Ventana Medical Systems, Inc., Tucson, Ariz.,USA) as shown in Table 1 below. Two slides were stained under each setof experimental condition. The assay process images were captured by theRTAM system at 0.5 fps starting at the moment the DAB detection reagentswere dispensed onto the slides.

TABLE 1 Reagents Time (minutes) DAB 8 8 8 8 8 8 8 4 CD-20 16  12 8 4 1616 16 4 Antibody Hematoxylin 4 4 4 4 16 12 8 4 Control

As mentioned above, a saturation index was utilized for the thin filmstaining environment of FIG. 2, and in comparison with pathologists'intensity scoring had reached a correlation of R²=0.89 (see, FIG. 13).

FIG. 20 shows the correlation between pathologists' scores and thesaturation value in the puddle environment. The R² value is lower thanwhat was seen in the thin film environment. In contrast, as shown inFIG. 21, generation of the 8-bit grayscale index proved to reachoutstanding correlation (R²=0.94) with intensity score given bypathologists and thus demonstrated the feasibility of monitoring CD20assay in real time by a computer provided by the RTAMS to monitor theassay staining process of CD20 assay. Furthermore, these testsdemonstrated that the system can provide interpretive results before theassay ends, since RTAMS calculates the scores at the moment beforehematoxylin is dispensed onto the tissue samples, whereas thepathologists' scores were made after the slides had undergone thecomplete assay protocol.

Further evidence that RTAMS can monitor assay development in real timewas obtained by an experiment wherein only the antibody incubation timewas varied, but the DAB detection time was kept constant. Theexperimental conditions for this test are shown below in Table 2, andthe results are shown in FIG. 22, which clearly demonstrates acorrelation between the RTAMS grayscale score and the antibodyincubation time.

TABLE 2 Reagents Incubation Time (minutes) DAB 8 8 8 8 CD-20 16 12 8 4Antibody

RTAMS can also be used to calculate a percentage of positive cells of inthe CD20 according to the embodiment of FIG. 23. In the CD20 assay,three colors are evident in the images: brown for the DAB signal, lightblue for the counterstaining signal and a white background, as is shownin Panel A of FIG. 23. As illustrated in Panel B of FIG. 23, K-meansclustering in HSV color space can be used to separate brown with othercolors. And then, threshold setting in RGB color space is used to divideblue from white background. This particular example calculates an indexbased on pixels instead of cells, wherein the % positive cells iscalculated by dividing the number of brown pixels by the sum of brownand blue pixels and multiplying by 100. A possible alternative to thismethod is to utilize machine learning method to build a classifier toseparate stained cell and non-stained cells and arrive at a percent %cells. Since such measures of % positive cells can be obtained duringthe assay, it is possible to provide a logic module as part of theautomated test ordering system 28 of FIG. 1, wherein if for a given testa predetermined number of cells in a sample are positive for aparticular marker, a second (and possibly third, fourth or more) test isautomatically ordered before the first test is finished. Alternatively,a test result (for example, a result upon which a particular therapydecision could be made) could be output from controller 12 immediatelyupon the number of positive cells reaching a predetermined value.

Another embodiment of the disclosed real time assay system and methodincludes a system and method for separating the portion of a sampleimage that is stained by DAB (brown) and a Red chromogen. Setting athreshold in RGB channel is no longer a proper method for colordetection since both brown and red contain main intensity in the Rchannel for a DAB/Red assay. Therefore, k-means clustering in variouscolor spaces including RGB, HSV and L*a*b* was tested. As a result,k-means clustering in RGB color space was found to be the optimalsolution for color detection in DAB/Red assay. The overall scheme ofthis embodiment is shown in FIG. 24.

The strategy, however, could be altered other combinations ofthresholding, segmenting, clustering and color spaces as needed forother assays having different colors. Although the figures herein mayshow a specific order of method steps, the order of the steps may differfrom what is depicted. Also, two or more steps may be performedconcurrently or with partial concurrence. Variations in step performancecan depend on the software and hardware systems chosen and on designerchoice. All such variations are within the scope of the application.Software implementations could be accomplished with standard programmingtechniques, with rule based logic and other logic to accomplish thevarious connection steps, processing steps, comparison steps anddecision steps.

It should be understood that the identified embodiments are offered byway of example only. Other substitutions, modifications, changes andomissions may be made in the design, operating conditions andarrangement of the embodiments without departing from the scope of thepresent application. Accordingly, the present application is not limitedto a particular embodiment, but extends to various modifications thatnevertheless fall within the scope of the application. It should also beunderstood that the phraseology and terminology employed herein is forthe purpose of description only and should not be regarded as limiting.

As used herein, the singular terms “a,” “an,” and “the” include pluralreferents unless the context clearly indicates otherwise. Similarly, theword “or” is intended to include “and” unless the context clearlyindicates otherwise.

The terms “comprising,” “including,” “having,” and the like are usedinterchangeably and have the same meaning. Similarly, “comprises,”“includes,” “has,” and the like are used interchangeably and have thesame meaning. Specifically, each of the terms is defined consistent withthe common United States patent law definition of “comprising” and istherefore interpreted to be an open term meaning “at least thefollowing,” and is also interpreted not to exclude additional features,limitations, aspects, etc. Thus, for example, “a device havingcomponents a, b, and c” means that the device includes at leastcomponents a, b and c. Similarly, the phrase: “a method involving stepsa, b, and c” means that the method includes at least steps a, b, and c.Moreover, while the steps and processes may be outlined herein in aparticular order, the skilled artisan will recognize that the orderingsteps and processes may vary unless a particular order is clearlyindicated by the context.

What is claimed is:
 1. A computer implemented method of monitoring aspecimen undergoing an assay, the method comprising: capturing an imageof a specimen undergoing an assay with an imaging system comprising acamera, wherein the specimen is disposed on a substrate; selecting aregion of the captured image, the region including at least a portion ofthe specimen undergoing the assay; calculating a saturation index valuefor the selected region of the captured image; converting the calculatedsaturation index value to a signal intensity score using a predeterminedcorrelation based on experimental data; evaluating the specimenundergoing the assay using the signal intensity score; and controllingthe assay in real-time based on the evaluation of the specimen, saidselecting the region includes selecting a plurality of regions of thecaptured image; said calculating the index value includes calculating arespective index value for each region of the plurality of regions; themethod further comprises comparing the calculated index values for eachregion of the plurality of regions; and determining a non-uniformspecimen undergoing the assay in response to the comparison of thecalculated index values indicating differences in the calculated indexvalues.
 2. The method of claim 1, wherein: the captured image includes amatrix with values representing a color of each pixel, wherein the colorof each pixel is defined by an RGB color model; and said calculating theindex value includes calculating a grayscale value from the color model.3. The method of claim 1, further comprising repeating at apredetermined interval during the assay said capturing the image, saidselecting the region, said calculating the index value, said convertingthe calculated index value and said evaluating the specimen.
 4. Themethod of claim 3, wherein said selecting a region includes selectingthe region at a substantially similar location for each predeterminedinterval.
 5. The method of claim 1, wherein said evaluating the specimenincludes evaluating a staining process of the specimen using the signalintensity score.
 6. The method of claim 5, wherein evaluating a stainingprocess of the specimen using the signal intensity score includesdetermining if a pre-determined value of the score is reached.
 7. Themethod of claim 6, further including at least one of alerting a userthat the pre-determined value was not reached within a pre-determinedamount of time, automatically ordering a repeat test if thepre-determined value is not reached within a pre-determined amount oftime, and automatically ordering a second, different test if thepre-determined value is reached during a pre-determined amount of time.8. A method of monitoring a fluid comprising: capturing an image of asample disposed on a slide undergoing an assay with an imaging system;determining a position of the sample, the position of the samplecorresponding to a position of a fluid either on the sample or on theslide; calculating a fluid volume based on the captured image inresponse to the determined position of the sample being in apredetermined position; determining an adjustment amount of the fluidbased on the calculated fluid volume; and adjusting the amount of thefluid in the sample based on the adjustment amount, wherein thecalculating of the fluid volume includes determining at least oneboundary of the fluid from the captured image, wherein the boundary ofthe fluid is detected using a Gaussian mixture model when the fluid is aclear fluid or a color-thresholding method when the fluid is a stain. 9.The method of claim 8, wherein said determining the position of thesample includes determining a direction of movement of fluid in thesample.
 10. The method of claim 8, wherein the sample is held in a fluidmotion mechanism and wherein said determining the position of the sampleincludes determining a position of the fluid motion mechanism.
 11. Themethod of claim 10, wherein the predetermined position is offset from acenter position of the fluid motion mechanism.
 12. A computerimplemented method of monitoring a specimen undergoing an assay, themethod comprising: capturing an image of a first specimen undergoing afirst assay with an imaging system; selecting a region of the capturedimage, the region including at least a portion of the first specimenundergoing the first assay; segmenting the image into one or more colorswithin a color space using k-means clustering; identifying pixels in theimage that correspond to a particular type of cell; identifying pixelsin the image that correspond to cells not of the particular type ofcell; and, calculating a percentage of the first specimen including theparticular type of cell, determining whether the calculated percentagemeets a predetermined threshold; and if the calculated percentage meetsor exceeds the predetermined threshold, automatically performing asecond assay before the first assay is complete.
 13. The computerimplemented method of claim 12, wherein the second assay is performed onthe first specimen.
 14. The computer implemented method of claim 12,wherein the second assay is performed on a second specimen.
 15. Acomputer implemented method of monitoring a specimen undergoing anassay, the method comprising: capturing an image of the specimenundergoing an assay with an imaging system comprising a camera, whereinthe specimen is disposed on a slide; selecting a region of the capturedimage, the region including at least a portion of the specimenundergoing the assay; calculating a saturation index value for theselected region of the captured image; converting the calculatedsaturation index value to a signal intensity score using experimentallypredetermined correlations between saturation index values and signalintensity scores; determining if a pre-determined value of the score isreached within a pre-determined amount of time: and, a) alerting a userthat the pre-determined value was not reached within the pre-determinedamount of time, b) automatically ordering a repeat test if thepre-determined value is not reached within the pre-determined amount oftime, or c) automatically ordering a second, different test if thepre-determined value is reached during the pre-determined amount oftime.
 16. The method of claim 15, further comprising using one or moreindex values and one or more signal intensity scores to calculate apercentage of cells that are positive according to the assay.
 17. Acomputer implemented method of monitoring a specimen undergoing anassay, the method comprising: capturing an image of a specimenundergoing an assay with an imaging system comprising a camera, whereinthe specimen is disposed on a substrate; selecting a region of thecaptured image, the region including at least a portion of the specimenundergoing the assay; calculating a saturation index value for theselected region of the captured image; converting the calculatedsaturation index value to a signal intensity score using a predeterminedcorrelation based on experimental data; evaluating the specimenundergoing the assay using the signal intensity score; and controllingthe assay in real-time based on the evaluation of the specimen, whereinsaid evaluating the specimen includes evaluating a staining process ofthe specimen using the signal intensity score, wherein evaluating astaining process of the specimen using the signal intensity scoreincludes determining if a pre-determined value of the score is reached,further including at least one of alerting a user that thepre-determined value was not reached within a pre-determined amount oftime, automatically ordering a repeat test if the pre-determined valueis not reached within a pre-determined amount of time, and automaticallyordering a second, different test if the pre-determined value is reachedduring a pre-determined amount of time.